Template-free mechanochemical route to prepare crystalline and electroactive polydiphenylamine nanostructures

A facile and sustainable mechanochemical route for the synthesis of undoped polydiphenylamine (PDPA) and inorganic acid doped nanostructures are reported. Field emission scanning electron microscopic (FESEM) images highlighted the formation of distinctly different nanostructures for each of the inorganic acid doped PDPA. Elemental analysis carried out for the polymers revealed the presence of more repeating units in their backbone. The X-ray diffraction (XRD) results of the as-prepared PDPA nanostructures indicated the high degree of crystallinity ever reported for PDPA. Spectroscopic profile of the polymers showed that the prepared PDPA is in a doped conducting form. Electrochemical studies performed for the polymeric particles ascertained the redox behaviour and the good electrochemical activity of obtained PDPA samples. The probable mechanistic aspect behind the formation of PDPA nanostructures through this simple and efficient route is discussed.

Graphical abstract. The facile mechancochemical synthetic methodology produces different polydiphenylamine nanostructures by simple variation of dopant acids. The resultant polymers are highly crystalline and conductive. The sustainable nature of the reported methodology makes it a cleaner reaction route to prepare different polydiphenylamine nanostructures in good yield.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Nanostructures of polydiphenylamines doped with different inorganic acids were prepared through facile template-free route. ► The prepared polydiphenylamine salts are found to possess good crystallintity and electrochemical activity. ► The melt formed during the solid-state reaction is supposed to play a crucial role in determining the surface morphology of the final polymeric product.